Cornell researchers have 3-D printed a working loudspeaker, seamlessly integrating the plastic, conductive and magnetic parts, and ready for use almost as soon as it comes out of the printer.

It’s an achievement that 3-D printing evangelists feel will soon be the norm; rather than assembling consumer products from parts and components, complete functioning products could be fabricated at once, on demand.

The loudspeaker is a project led by Apoorva Kiran and Robert MacCurdy, graduate students in mechanical engineering, who work with Hod Lipson, associate professor of mechanical and aerospace engineering, and a leading 3-D printing innovator.

“Everything is 3-D printed,” said Kiran, as he launched a demo by connecting the newly printed mini speaker to amplifier wires. For the demo, the amplifier played a clip from President Barack Obama’s State of the Union speech that mentioned 3-D printing.

A loudspeaker is a relatively simple object, Kiran said: It consists of plastic for the housing, a conductive coil and a magnet. The challenge is coming up with a design and the exact materials that can be co-fabricated into a functional shape.

Lipson said he hopes this simple demonstration is just the “tip of the iceberg.” 3-D printing technology could be moving from printing passive parts toward printing active, integrated systems, he said.

But it will be a while before consumers are printing electronics at home, Lipson continued. Most printers cannot efficiently handle multiple materials. It’s also difficult to find mutually compatible materials – for example, conductive copper and plastic coming out of the same printer require different temperatures and curing times.

In the case of the speaker, Kiran used one of the lab’s Fab@Homes, a customizable research printer originally developed by Lipson and former graduate student and lab member Evan Malone, that allows scientists to tinker with different cartridges, control software and other parameters. For the conductor, Kiran used a silver ink. For the magnet, he employed the help of Samanvaya Srivastava, graduate student in chemical and biomolecular engineering, to come up with a viscous blend of strontium ferrite.